| 摘要 |
A device for automatically determining the deviation between the structures of a pattern and those of an object compared therewith, in which the structures to be compared are viewed superimposed on a measurement gap, whereby a polarisation characteristic is given to the individual picture channels. As the result of the relative movement between the superimposed object picture and the measurement gap, and the subsequent separation of the picture channels according to their polarization characteristic, photometric signal curves are obtained from which errors in the overlap of the structures can be quantatively determined. By introducing a picture rotation prism, measurements can be made in two co-ordinate directions. In a branched observation beam path the polarization characteristic is converted into a colour characteristic, so that an additional representation of the combined picture of the structure overlap is produced. The photometric scanning range can be made visible by back-lighting of the measurement gap and reflection into the observation beam path. |
